The proprietors of various types of government facilities, businesses and private properties find it necessary or desirable to limit vehicular access to their grounds or buildings. For reasons of security or for other purposes, only authorized vehicles are permitted to enter at a given gate or to pass through some restricted area.
An automatic detection and control system may be advantageously employed to provide this form of security. Such an automatic system may serve a fleet of vehicles owned by an operation and might, in addition to restricting entry, provide an instant record of the specific vehicles present on the grounds or in a security-sensitive area. In residential applications the system might grant immediate access to residents while holding visitors for screening prior to entry. At a hospital such a system might be employed to signal the arrival, presence or departure of a physician's vehicle, thereby indicating the presence or absence of the physician himself.
Such an automatic access control system should ideally provide rapid or instantaneous identification and should deliver data relative to entering vehicles in a form that may be readily processed to control the entry gates or alarms or to generate permanent records of system activity. The degree of manual intervention required (e.g. the use of keys, coded cards, etc.) should be minimized, and the system should be designed to prevent or discourage tampering with or circumvention of its intended operation.